s3: throw any copy errors

(cherry picked from commit 40bcfdba76)

src/storage/s3.js

@@ -454,6 +454,7 @@ async function copy(apiConfig, oldFilePath, newFilePath, progressCallback) {
     }));
 
     progressCallback({ message: `Copied ${total} files with error: ${copyError}` });
+    if (copyError) throw copyError;
 }
 
 async function remove(apiConfig, filename) {